Delayed venting in a curtain airbag

ABSTRACT

An airbag, or inflatable curtain airbag assembly, can include one or more chambers and vents. The vents can be in fluid communication with one or more of the chambers. The vents can be configured to delay passage of inflation gas from an interior of the airbag into an interior chamber or to an exterior of the airbag upon deployment of the airbag. The vents can also be configured to transition from a closed configuration to an open configuration when an internal pressure of the airbag reaches a predetermined value.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of now pending U.S. patent applicationSer. No. 13/844,733, filed Mar. 15, 2013, entitled “DELAYED VENT INAIRBAG CURTAIN,” the entire contents of which are hereby incorporatedherein by reference.

BACKGROUND

Airbags are often mounted to a vehicle and deploy so as to prevent anoccupant from impacting vehicular structures and/or to prevent anoccupant from being ejected from a vehicle in a collision. In someinstances, the airbags can suffer from one or more drawbacks or mayperform less than optimally in one or more respects. Embodimentsdisclosed herein provide improvement in performance of airbags.

BRIEF DESCRIPTION OF THE DRAWINGS

The written disclosure herein describes illustrative embodiments thatare non-limiting and non-exhaustive. Reference is made to certain ofsuch illustrative embodiments that are depicted in the figures, inwhich:

FIG. 1A is an elevation view of an embodiment of an inflatable curtainairbag assembly mounted within a vehicle, wherein the assembly is shownin a packaged configuration;

FIG. 1B is another elevation view of the inflatable curtain airbagassembly of FIG. 1A shown in a deployed configuration;

FIG. 2 is an elevation view of an embodiment of an inflatable curtainairbag that is compatible with the inflatable curtain airbag assembly ofFIGS. 1A and 1B;

FIG. 3 is an elevation view of another embodiment of an inflatablecurtain airbag that is compatible with the inflatable curtain airbagassembly of FIGS. 1A and 1B;

FIG. 4 is a graph comparing values of occupant acceleration and occupantdisplacement into an airbag;

FIG. 5A is an elevation view of another embodiment of an inflatablecurtain airbag assembly mounted within a vehicle, wherein the assemblyis shown in a packaged configuration;

FIG. 5B is another elevation view of the inflatable curtain airbagassembly of FIG. 5A shown in a deployed configuration;

FIG. 6 is an elevation view of an embodiment of an inflatable curtainairbag that is compatible with the inflatable curtain airbag assembly ofFIGS. 5A and 5B;

FIG. 7 is an elevation view of another embodiment of an inflatablecurtain airbag that is compatible with the inflatable curtain airbagassembly of FIGS. 5A and 5B;

FIG. 8 is an elevation view of another embodiment of an inflatablecurtain airbag that is compatible with the inflatable curtain airbagassembly of FIGS. 1A and 1B;

FIG. 9A is an enlarged cross-sectional view of the inflatable curtainairbag of FIG. 8 taken along line 9A-9A depicting an embodiment of aventing panel in a closed configuration;

FIG. 9B is an enlarged cross-sectional view of the inflatable curtainairbag of FIG. 8 taken along line 9A-9A depicting the embodiment of theventing panel of FIG. 9A in an open configuration;

FIG. 10 is an elevation view of another embodiment of an inflatablecurtain airbag that is compatible with the inflatable curtain airbagassembly of FIGS. 1A and 1B;

FIG. 11 is an elevation view of another embodiment of an inflatablecurtain airbag that is compatible with the inflatable curtain airbagassembly of FIGS. 1A and 1B;

FIG. 12 is an elevation view of another embodiment of an inflatablecurtain airbag that is compatible with the inflatable curtain airbagassembly of FIGS. 1A and 1B;

FIG. 13A is an enlarged cross-sectional view of the inflatable curtainairbag of FIG. 12 taken along line 13A-13A depicting an embodiment of aventing panel in a closed configuration;

FIG. 13B is an enlarged cross-sectional view of the inflatable curtainairbag of FIG. 12 taken along line 13A-13A depicting the embodiment ofthe venting panel of FIG. 13A in an open configuration;

FIG. 14A is an enlarged cross-sectional view of the inflatable curtainairbag of FIG. 12 taken along line 13A-13A depicting another embodimentof a venting panel in a closed configuration;

FIG. 14B is an enlarged cross-sectional view of the inflatable curtainairbag of FIG. 12 taken along line 13A-13A depicting the embodiment ofthe venting panel of FIG. 14A in an open configuration;

FIG. 15 is an elevation view of another embodiment of an inflatablecurtain airbag that is compatible with the inflatable curtain airbagassembly of FIGS. 1A and 1B;

FIG. 16 is an elevation view of another embodiment of an inflatablecurtain airbag that is compatible with the inflatable curtain airbagassembly of FIGS. 1A and 1B;

FIG. 17A is an elevation view of another embodiment of an inflatablecurtain airbag that is compatible with the inflatable curtain airbagassembly of FIGS. 1A and 1B shown in a coupled configuration;

FIG. 17B is an elevation view of another embodiment of an inflatablecurtain airbag that is compatible with the inflatable curtain airbagassembly of FIGS. 1A and 1B shown in an uncoupled configuration.

DESCRIPTION

It will be readily understood that the components of the embodiments asgenerally described and illustrated in the figures herein could bearranged and designed in a wide variety of different configurations.Thus, the following more detailed description of various embodiments, asrepresented in the figures, is not intended to limit the scope of thepresent disclosure, but is merely representative of various embodiments.While the various aspects of the embodiments are presented in drawings,the drawings are not necessarily drawn to scale unless specificallyindicated.

The phrases “connected to” and “coupled to” are used in their ordinarysense, and are broad enough to refer to any suitable coupling or otherform of interaction between two or more entities, including mechanical,fluid and thermal interaction. Two components may be coupled to eachother even though they are not in direct contact with each other. Thephrases “attached to” or “attached directly to” refer to interactionbetween two or more entities which are in direct contact with each otherand/or are separated from each other only by a fastener of any suitablevariety (e.g., mounting hardware or an adhesive). The phrase “fluidcommunication” is used in its ordinary sense, and is broad enough torefer to arrangements in which a fluid (e.g., a gas or a liquid) canflow from one element to another element when the elements are in fluidcommunication with each other.

Inflatable airbag systems are widely used to reduce or minimize occupantinjury in a collision scenario. Airbag modules have been installed atvarious locations within a vehicle, including, but not limited to, thesteering wheel, the instrument panel, within the side doors or sideseats, adjacent to the roof rail of the vehicle, in an overheadposition, or at the knee or leg position. In the following disclosure,“airbag” generally refers to an inflatable curtain airbag or cushion,although the principles discussed may apply to other airbag types inother embodiments.

Inflatable curtain airbags typically extend longitudinally within thevehicle and are usually coupled to or next to the roof rail of thevehicle. In an undeployed state, inflatable curtain cushions aretypically rolled and/or folded, and may be retained in the undeployedconfiguration by being wrapped in a restraint at various attachmentpoints at which the inflatable airbag is attached to the vehicle, or bybeing enclosed in a restraint, such as a sleeve or sock. In a deployedstate, an inflatable curtain cushion may expand and burst free from therestraint to cover at least a portion of the side windows and one ormore pillars of the vehicle. In some embodiments, inflatable curtaincushions may cover one or more of the A-, B-, C-, and D-pillars of avehicle. For example, in some embodiments, the inflated curtain airbagmay extend from the A-pillar to the C-pillar of the vehicle. In otherembodiments, a deployed inflatable curtain cushion may extend from theA-pillar to the D-pillar of the vehicle.

In a collision event, the inflatable curtain cushion may be inflated byan inflator and change conformation from being rolled and/or folded inthe packaged state to being extended and/or inflated in a deployedstate. In some arrangements, the amount of gas from the inflator that isretained within the inflatable curtain determines how hard or soft thecushioning of the curtain will be. Other factors may also affect thecushioning abilities of the inflatable curtain airbag.

Some inflatable curtain cushions may be configured to serve dualfunctions of cushioning and ejection prevention. During a collisionevent, the curtain may cushion the head and upper body of an occupant,and during a roll-over event, the cushion may function to help retainthe occupant within the vehicle. Inflatable curtain cushions helpmitigate the risk of occupant ejection by forming a barrier between theoccupant and the side windows.

Some inflatable airbags have a throat portion that is in fluidcommunication with an inflator. The inflator may be configured togenerate inflation gas in response to predetermined conditions. Theinflatable airbag may comprise one or more voids or chambers forreceiving the inflation gas. The throat liner may be positioned in thevoid of the inflatable airbag at the throat portion. In some instancesthe throat liner may extend beyond the throat portion along alongitudinal length of the inflatable airbag. Throat liners of anylength and at any position within the void of the throat portion and/orthe inflatable airbag are within the scope of this disclosure.

In some embodiments, the throat liner may be made of the same materialas the throat portion and the inflatable airbag. In other embodiments,the throat liner may be made of a different material than the throatportion and/or the inflatable cushion. The materials may have differentstrengths, melting temperatures, and other relevant properties.

In some embodiments, the inflatable curtain airbags disclosed herein maybe configured to vent inflation gas in a controlled or delayed mannerfrom one or more chambers or segments of the airbag. Such controlled ordelayed venting of the inflatable cushion segments may soften thecushioning provided by the deployed inflatable airbag. Inflatablecurtain airbags with varying levels of hardness in different portions orsegments of the airbag may be desirable.

FIGS. 1A and 1B depict an embodiment of an inflatable curtain airbagassembly 100 mounted within a vehicle 50. In FIG. 1A, the assembly 100is in a packaged configuration, whereas in FIG. 1B, the assembly 100 isin a deployed configuration.

With reference to FIG. 1A, the assembly 100 can include an inflatablecurtain airbag 120 (see also FIG. 1B), which can be secured to thevehicle 50 in any suitable manner. The inflatable curtain airbag 120 mayalso be referred to herein as a cushion or as an airbag. In theillustrated embodiment, the inflatable curtain airbag 120 is positionedat an interior of a restraint 102 so as to be retained in a packagedconfiguration. The restraint 102 may be of any suitable variety, such asone or more straps, tethers, socks, or sleeves. In the illustratedembodiment, the restraint 102 comprises a sleeve that extends alongsubstantially a full length of the inflatable curtain airbag 120, suchthat a majority of the inflatable curtain airbag 120 is obscured fromview by the sleeve in FIG. 1A.

The assembly 100 can be attached to the vehicle 50 in any suitablemanner. For example, in some embodiments, the assembly 100 includes oneor more fastening assemblies 110 that are configured to secure one ormore of the inflatable curtain airbag 120 and the restraint 102 to thevehicle 50. The assembly 100 can be mounted inside the vehicle 50adjacent to a roof of the vehicle, such as to a roof rail 52. In theillustrated embodiment, each fastening assembly 110 includes a tether orstrap 116 that is secured to mounting hardware, such as a tab 112 thatis secured to the roof rail 52 via a fastener 114, such as a bolt. Anyother suitable fastening arrangement is contemplated. Each strap 116 maybe coupled with one or more of the inflatable curtain airbag 120 and therestraint 102 in any suitable manner.

A forward end of the assembly 100 can include a strap 104, which may besecured to the vehicle in any suitable manner. For example, in theillustrated embodiment, the strap 104 is attached to a lower end of anA-pillar 62. As shown in FIG. 1B, the strap 104 can be attached to aforward end 124 of the inflatable curtain airbag 120. An upper end 122of the inflatable curtain airbag 120 can be attached to the straps 116.In some embodiments, the straps 116 are sewn to the inflatable curtainairbag 120. In other embodiments, the straps 116 may be integrallyformed with the inflatable curtain airbag 120, and may extend from oneor more panels of the inflatable cushion 120.

With continued reference to FIG. 1A, the assembly can further include aninflator 118, which may be positioned within a throat 126 of theinflatable curtain airbag 120. The inflator 118 can be anchored to theroof rail 52, and may be of any suitable variety. In some embodiments,the inflator 118 comprises either a pyrotechnic device or a stored gasinflator. The inflator 118 can be in electronic communication withvehicle sensors which are configured to detect vehicle collisions and/orrollovers. Upon detection of predetermined conditions, the sensors canactivate the inflator 118 and the inflatable curtain airbag 120 may berapidly inflated.

With reference to FIGS. 1A and 1B, the inflatable curtain airbag 120 canbe configured to cover various structures of the vehicle 50 whendeployed. For example, in some embodiments, at least a portion of thedeployed inflatable curtain airbag 120 can cover one or more of theA-pillar 62, a B-pillar 64, and a C-pillar 66, and/or one or more sidewindows 70. The illustrated embodiment is configured to cover theB-pillar 64, and each of the side windows 70.

With reference to FIG. 1B, the inflatable curtain airbag 120 can definevarious portions that provide different amounts of cushioning relativeto the vehicle structures. In particular, the inflatable curtain airbag120 can include various inflatable chambers, cells, or cushion segmentsthat are configured to be filled with inflation gases in order tocushion a vehicle occupant during a collision event. The inflatablecushion segments 142 can be configured to deploy at strategic areas atwhich a vehicle occupant may benefit most from the cushioning. Theillustrated embodiment includes a plurality of inflatable cushionsegments 142 that are in fluid communication with an inflation gasdelivery channel 140. In some embodiments, inflation gases may beretained within a given inflatable cushion segment 142 to maintain theinflatable cushion segment 142 in an inflated or filled configuration,even when a vehicle occupant presses against the inflatable cushionsegment 142. Such an arrangement can allow the inflatable cushionsegment 142 to provide a desired amount of protection to the vehicleoccupant.

In some embodiments, the inflatable curtain airbag 120 can include oneor more non-inflatable regions 144, one or more of which may bepositioned between adjacent inflatable cushion segments 142 or at aninterior of an inflatable cushion segment 142 (e.g., so as to beencompassed by an inflatable cushion segment 142).

In various embodiments, at least a portion of one or more of theinflatable cushion segments 142 and the non-inflatable regions 144 canbe defined by one or more boundary seams 150. The one or more boundaryseams 150 may be formed in any suitable manner. For example, in someembodiments, the one or more boundary seams 150 may comprise one or moreof stitches, welds (e.g., radiofrequency welds), and/or adhesives. Inother or further embodiments, the boundary seams 150 may be wovenportions that are formed via one-piece weaving techniques. As furtherdiscussed below, in some embodiments, the boundary seams 150 may jointogether two or more pieces of fabric, such as a front face 132 and arear face 134. In some embodiments, the one or more boundary seams 150are substantially airtight so as to be able to retain inflation gaswithin a given inflatable cushion segment 142. The one or more boundaryseams 150 can be said to fluidly isolate adjacent inflatable cushionsegments 142 from each other. In other embodiments, the one or moreboundary seams 150 may not be airtight, but may instead resist egress ofgases from an inflatable cushion segment 142.

The shapes of the inflatable curtain airbag 120 and its variouscomponents, such as the segments 142, that are depicted in FIG. 1B arenot necessarily limiting. These shapes may be altered, such as toaccommodate differently shaped vehicles. In some embodiments, theinflated inflatable curtain airbag 120 is configured to fit within theside window wells of vehicle 50. The inflatable curtain airbag 120 maycomprise a contiguous piece of material manufactured using a one-piecewoven technique, in some embodiments, or in other or furtherembodiments, may be manufactured by cutting and sewing separate piecesof material (e.g., nylon fabric) together. For example, the front andrear faces 132, 134 may be formed from separate sheets of material thatare joined together. In other embodiments, the front and rear faces 132,134 may be formed from a unitary piece of material.

As can be appreciated from FIGS. 1A and 1B, when the inflatable curtainairbag 120 is in the packaged configuration, all components of theinflatable curtain airbag 120 can be at an interior of the restraint102. In the illustrated embodiment, the restraint 102 is a sleeve thatcovers an entirety of the inflatable curtain airbag 120. However, inother embodiments, the restraint 102 may merely comprise a plurality ofstraps, and each strap may encompass a portion of various components ofthe inflatable curtain airbag 120, such as, for example, portions of theinflation gas delivery channel 140.

FIG. 2 depicts another embodiment of an inflatable curtain airbag 220that can resemble the inflatable curtain airbag 120 described above incertain respects, and that can be compatible with the assembly 100.Accordingly, like features are designated with like reference numerals,with the leading digits incremented to “2.” Relevant disclosure setforth above regarding similarly identified features thus may not berepeated hereafter. Moreover, specific features of the inflatablecurtain airbag 220 may not be shown or identified by a reference numeralin the drawings or specifically discussed in the written descriptionthat follows. However, such features may clearly be the same, orsubstantially the same, as features depicted in other embodiments and/ordescribed with respect to such embodiments. Accordingly, the relevantdescription of such features applies equally to the features of theinflatable curtain airbag 220. Any suitable combination of the featuresand variation of the same described with respect to the inflatablecurtain airbag 120 can be employed with the inflatable curtain airbag220, and vice versa. This pattern of disclosure applies equally tofurther embodiments depicted in subsequent figures and describedhereafter, wherein the leading digits may be further incremented.

Referring to FIG. 2, the inflatable curtain airbag 220 has alongitudinal orientation and includes a throat portion 226 at a proximalend. As used herein, the terms proximal and distal refer to proximity tothe inflator 118 and/or direction of inflation gas flow duringdeployment, where more proximally oriented features are closer to theinflator 118 and/or contact inflation gases sooner than do more distallyoriented features. The throat portion 226 may be configured to receiveat least a portion of an inflator 118 therein and/or to be coupled withthe inflator 118. As illustrated, the inflatable curtain airbag 220includes a front face 232 and a rear face 234 that meet at an edge 254.The front face 232 and the rear face 234 cooperate to define a void orchamber for receiving an inflation gas from the inflator 118. In theillustrated embodiment, the inflatable curtain airbag 220 furthercomprises a boundary seam 250 adjacent to the edge 254 of the inflatablecurtain airbag 220. The boundary seam 250 also defines the one or moreinflatable cushion segments 242 and non-inflatable regions 244. In theillustrated embodiment, the inflatable cushions segments 242 are influid communication with each other. In some embodiments, the inflatablecushion segments 242 may not be in fluid communication with one another,and in other embodiments, only a portion of a total number of inflatablecushion segments 242 may be in fluid communication with one another. Theone or more boundary seams 250 may fluidly seal the void of theinflatable cushion 220. In yet other embodiments, the one or moreboundary seams 250 may not be airtight but may instead resist egress ofgasses from the void of the inflatable cushion 220.

As illustrated, the inflatable curtain airbag 220 further includes athroat liner 227 in fluid communication with and disposed within atleast a portion of the throat portion 226. In some embodiments, thethroat liner 227 may comprise an aperture for passage of the inflationgas into the inflatable curtain airbag 220. In other embodiments, thethroat liner 227 may comprise two panels that cooperate to form theaperture for passage of the inflation gas into the inflatable curtainairbag 220. In yet other embodiments, the throat liner 227 may be formedfrom a unitary piece of material. For example, the throat liner 227 maybe woven by a one-piece woven technique.

The throat liner 227 may also be configured to receive at least aportion of the inflator 118 therein and/or to be coupled with theinflator 118. In the illustrated embodiment, the throat liner 227comprises an opening 228 at a position distal to the inflator 118 and avent 230 spaced along a longitudinal length of the throat liner 227. Insome embodiments, the throat liner 227 can comprise one or more vents230 spaced along the longitudinal length of the throat liner 227. Theone or more vents 230 and/or openings 228 can be configured toselectively distribute the inflation gas into various portions and/orsegments of the inflatable curtain airbag 220. In the illustratedembodiment, the throat liner 227 extends in the longitudinal orientationof the inflatable curtain airbag 220 distally from the throat portion226. Throat liners 227, however, of various lengths and disposed atvarious positions within the inflatable curtain airbag 220 are alsowithin the scope of this disclosure.

Referring again to FIG. 2, the inflatable curtain airbag 220 comprisestwo chambers, a first chamber 236 and a second chamber 238, wherein avolume of the first chamber 236 is greater than a volume of the secondchamber 238. As shown, the first chamber 236 extends in a longitudinalorientation along about two-thirds of a length of the inflatable curtainairbag 220 and the second chamber 238 extends in a longitudinalorientation along about one-third of the length of the inflatablecurtain airbag 220. In some embodiments, the relative volumes and/orlengths of the first and second chambers 236, 238 may be different thandepicted in the illustrated embodiment. The second chamber 238 may bepositioned at or adjacent to a C-pillar 66 of a vehicle 50.Alternatively, the second chamber 238 may be positioned rearward to aB-pillar 64 of a vehicle 50. Each of the first and second chambers 236,238 comprise at least one inflatable cushion segment 242. Additionally,both of the first and second chambers 236, 238 are in fluidcommunication with the throat liner 227. In some embodiments, the firstand second chambers 236, 238 may be in fluid communication with eachother and with other components of the inflatable curtain airbag 220.For example, the first and second chambers 236, 238 may be coupled tothe throat portion 226 in embodiments that lack a throat liner 227. Asillustrated, the first chamber 236 comprises three inflatable cushionsegments 242, and the second chamber 238 comprises one inflatablecushion segment 242. In some embodiments, the first chamber 236 maycomprise more or less than three inflatable cushion segments 242.Likewise, the second chamber 238 may comprise more or less than oneinflatable cushion segment 242. The configuration, number, and/orpositioning of the inflatable cushion segments 242 can be designed so asto provide the inflatable curtain airbag 220 with desired protective andcushioning characteristics.

As illustrated, the second chamber 238 further comprises a substantiallyU-shaped tortuous vent 237, wherein the tortuous vent 237 is in fluidcommunication with an exterior of the inflatable curtain airbag 220. Thetortuous vent 237 is also in fluid communication with the inflatablecushion segment 242 of the second chamber 238. The tortuous vent 237 maycomprise a plurality of loops and/or turns. In other embodiments, thetortuous vent 237 may be substantially C-shaped, S-shaped, circuitous,or otherwise shaped. The shape of the tortuous vent may be configured todelay venting of the inflation gas from the void of the inflatablecurtain airbag 220.

The dashed arrows in FIG. 2 depict possible paths of the inflation gasas the inflation gas enters the inflatable curtain airbag 220 duringdeployment. A first portion of the inflatable gas may enter the firstchamber 236 and second portion of the inflation gas may enter the secondchamber 238. In the illustrated embodiment, the first portion of theinflation gas comprises a greater volume than the second portion of theinflation gas. As the inflation gas inflates the inflatable cushionsegments 242 the volume of the inflation gas in the inflatable curtainairbag 220 may reach a predetermined value. In some embodiments, thepredetermined value may be reached when the volume of inflation gas inat least one of the first and second chambers 236, 238 reaches aspecified level. When the volume of the inflation gas reaches thepredetermined value, the tortuous vent 237 may be configured to permitor allow passage of inflation gas through at least a portion of a lengthof the tortuous vent 237. In some embodiments, the predetermined valuemay be set to be reached when an occupant strikes the second chamber 238in a collision event.

The tortuous vent 237 may also be configured such that approximatelywhen the one or more inflatable cushion segments 242 of the secondchamber 238 are fully inflated, the inflation gas may begin to egressfrom a distal end of the tortuous vent 237, and the inflation gas maybegin to further egress to an exterior of the inflatable curtain airbag220. The inflatable curtain airbag 220 and/or the tortuous vent 237 mayalso be configured such that the inflation gas may exit the tortuousvent 237 at other desired time points.

FIG. 3 depicts another embodiment of an inflatable curtain airbag 320such as the inflatable curtain airbag 220 discussed above. Embodimentsof the inflatable curtain airbag 320 are compatible with embodiments ofthe assembly 100 discussed above. As shown in FIG. 3, inflatable curtainairbag 320 comprises a first chamber 336 and a second chamber 338. Thesecond chamber 338 comprises an inflatable cushion segment 342 in fluidcommunication with both of a throat liner 327 and a tortuous vent 337.As illustrated, the tortuous vent 337 is in fluid communication with athird chamber 339. Thus, tortuous vent 337 can vent inflation gasinternally into the third chamber 339. In this embodiment, the inflationgas may not egress to the exterior of the inflatable cushion segment320. Embodiments of the inflatable curtain airbags 320 may be desirablein vehicles where it is advantageous to contain the inflation gas withinthe inflatable curtain airbag 320.

FIG. 4 is a graph comparing values of vehicle occupant acceleration andvehicle occupant displacement into an airbag. The graph compares thesevalues in two embodiments, including a baseline airbag embodiment and adelayed vent airbag embodiment. The dotted line depicts valuesassociated with the baseline airbag embodiment, which is a sealed airbagthat does not comprise a vent. The solid line depicts values associatedwith the delayed vent airbag embodiment, which is an airbag with adelayed vent (e.g., such as tortuous vent 237) as disclosed herein. Thebaseline airbag may be stiffer, when fully deployed, than an airbagcomprising a vent. As depicted in FIG. 3, the baseline airbag has ahigher magnitude of acceleration than the delayed vent airbag. Further,the delayed vent may reduce the magnitude of acceleration of the delayedvent airbag as compared to the baseline airbag, and a delayed vent mayalso increase the magnitude of occupant displacement into the airbag ascompared to the baseline airbag. Such changes in magnitude may result inimproved cushioning abilities of the airbag.

FIGS. 5A and 5B depict another embodiment of an inflatable curtainairbag assembly 400 mounted within a vehicle 50 such as the inflatablecurtain airbag assembly 100 discussed above. In FIG. 5A, the assembly400 is in a packaged configuration, whereas in FIG. 5B, the assembly 400is in a deployed configuration.

The assembly 400 can further include an inflator 418, which may bepositioned within a throat portion 426 of the inflatable curtain airbag420. The inflator 418 can be anchored to the roof rail 52, and may be ofany suitable variety. Whereas the inflator 118 is anchored to thevehicle 50 adjacent to the C-pillar 66 forming an “end-fill”configuration, the inflator 418 is anchored to the vehicle 50 rearwardof the B-pillar 64 forming a “mid-fill” configuration. As described forinflator 118, upon detection of predetermined conditions, vehiclesensors can activate the inflator 418 and the inflatable curtain airbag420 may be rapidly inflated.

FIGS. 6 and 7 depict two additional embodiments of inflatable curtainairbags 520, 620 that can resemble the inflatable curtain airbags 220,320 described above in certain respects. Inflatable curtain airbags 520,620 are compatible with the assembly 400.

Referring to FIG. 6, the inflatable curtain airbag 520 has alongitudinal orientation and includes a throat portion 526 at a middleportion of the inflatable curtain airbag 520. The inflatable curtainairbag 520 includes a throat liner 527 in fluid communication with anddisposed within at least a portion of the throat portion 526. In theillustrated embodiment, the throat liner 527 comprises two openings 528at positions distal to the inflator 418. As shown, the throat liner 527extends in the longitudinal orientation of the inflatable curtain airbag520 distally from the throat portion 526.

As in inflatable curtain airbags 220, 320, inflatable curtain airbag 520comprises two chambers, a first chamber 536 and a second chamber 538. Asillustrated, the second chamber 538 further comprises a substantiallyU-shaped tortuous vent 537, wherein the tortuous vent 537 is in fluidcommunication with an exterior of the inflatable curtain airbag 520. Thetortuous vent 537 is also in fluid communication with the inflatablecushion segment 542 of the second chamber 538.

The dashed arrows in FIG. 6 depict possible paths of the inflation gasas the inflation gas enters the inflatable curtain airbag 520 duringdeployment. A first portion of the inflatable gas may enter the firstchamber 536 and second portion of the inflation gas may enter the secondchamber 538. In the illustrated embodiment, the first portion of theinflation gas comprises a greater volume than the second portion of theinflation gas. As the inflation gas inflates the plurality of inflatablecushion segments 542 the volume of the inflation gas in the secondchamber 538 may reach a predetermined value. When the volume of theinflation gas reaches the predetermined value, the tortuous vent 537 maybe configured to permit or allow passage of the inflation gas through atleast a portion of a length of the tortuous vent 537.

Referring to FIG. 7, inflatable curtain airbag 620 also comprises afirst chamber 636 and a second chamber 638. The second chamber 638comprises an inflatable cushion segment 642 in fluid communication withboth of a throat liner 627 and a tortuous vent 637. As illustrated, thetortuous vent 637 is in fluid communication with a third chamber 639.Thus, tortuous vent 637 can vent inflation gas internally into the thirdchamber 639. In this embodiment, the inflation gas may not egress to theexterior of the inflatable cushion segment 620, rather the inflatablegas egresses into a void of the third chamber 639.

Another embodiment of an inflatable curtain airbag 720 such as theinflatable curtain airbags 220, 320 discussed above, is depicted in FIG.8. Embodiments of the inflatable curtain airbag 720 are compatible withembodiments of the assembly 100 discussed above. The inflatable curtainairbag 720 has a longitudinal orientation and includes a throat portion726 at a proximal end. The throat portion 726 may be configured toreceive at least a portion of an inflator 118 therein and/or to becoupled with the inflator 118. As depicted, inflatable curtain airbag720 also comprises a throat liner 727 in fluid communication with anddisposed within at least a portion of the throat portion 726. Further,the throat liner 727 extends in the longitudinal orientation of theinflatable curtain assembly 720 distally from the throat portion 726. Asdescribed above, other throat liner 727 configurations are alsocontemplated.

FIG. 8 depicts an inflatable curtain airbag 720 including a firstchamber 736 and a second chamber 738 wherein a volume of the firstchamber is greater than a volume of the second chamber 738. As describedabove, however, other configurations of the first and second chambers736, 738 are contemplated. The first chamber 736 can comprise aplurality of inflatable cushion segments 742 that are in fluidcommunication with the throat liner 727. The second chamber 738 can beconfigured to receive inflation gas from one or more of the inflatablecushion segments 742. In some embodiments, the second chamber 738 canaid in controlling or maintaining an internal pressure of the inflatablecurtain airbag 720. For example, one or more second chambers 738 may aidin maintaining the internal pressure below a predetermined value. In theillustrated embodiment, the second chamber 738 is isolated from each ofthe inflatable cushion segments 742, the throat liner 727, the throatportion 726, and the inflator 118 by a venting panel 758. Further, theinflatable curtain airbag 720 comprises one second chamber 738 distallydisposed in the inflatable curtain airbag 720 relative to each of theventing panel 758, the inflatable cushion segments 742, and the throatportion 726. The inflatable curtain airbag 720, as illustrated,comprises one venting panel 758 extending in a substantially transversedirection relative to the longitudinal orientation of the inflatablecurtain airbag 720.

In other embodiments, there may be more than one second chamber 738and/or more than one venting panel 758. In embodiments, the one or moreventing panels 758 may define a boundary of one or more of theinflatable cushion segments 742. The one or more second chambers 738and/or venting panels 758 may also be disposed at any suitable positionin the inflatable curtain airbag 720, as described more fully below inother embodiments.

In the illustrated embodiment, the venting panel 758 comprises aplurality of slits 760 or openings. FIGS. 9A and 9B are enlargedcross-sectional views of the inflatable curtain airbag of FIG. 8 takenalong line 9A-9A depicting an embodiment of a venting panel 758. Theventing panel 758 of FIG. 9A is in a closed configuration and theventing panel 758 of FIG. 9A in an open configuration. The slits 760 canbe configured to transition from a closed configuration (as in FIG. 9A)to an open configuration (as in FIG. 9B) when a volume of inflation gasin the first chamber 736 reaches a predetermined value. In otherembodiments, the slits 760 can be configured to transition from a closedconfiguration to an open configuration when an interior pressure of thefirst chamber 736 reaches a predetermined value. The size and/or theshape of the slits can be designed such that the slits transition from aclosed configuration to an open configuration when the pressuredifferential across the slits reaches a predetermined value. Forexample, slits with smaller dimensions may require a greater pressuredifferential across the slits to transition the slits from a closedconfiguration to an open configuration than may be required for slitswith larger dimensions. In another embodiment, the predetermined valuemay be reached when a vehicle occupant strikes a deployed inflatablecurtain airbag 720 during a collision event.

Referring again to FIG. 8, in some embodiments, the venting panel 758may define the boundary between the second chamber 738 and inflatablecushion segment 742 a, and inflatable cushion segment 742 a may beconfigured to deflate more quickly than the remaining inflatable cushionsegments 742 of the first chamber 736. Additionally, the venting panel758 may prevent the inflation gas from moving from the inflatablecushion segments into the second chamber 738 when the slits 760 are in aclosed configuration. Also, the venting panel 758 may permit theinflation gas to move more easily from the inflatable cushion segments742 into the second chamber 738 when the slits 760 are in an openconfiguration.

FIG. 10 depicts another embodiment of an inflatable curtain airbag 820such as the inflatable curtain airbag 720 discussed above. Embodimentsof the inflatable curtain airbag 820 are compatible with embodiments ofassembly 100 discussed above. A first inflatable cushion segment 842 ofthe inflatable curtain airbag 820 is positioned proximally to the throatportion 826 and below the throat liner 827. A second chamber 838 ispositioned distally to the first inflatable cushion segment 842. Theventing panel 858 defines a boundary between the first inflatablecushion segment 842 and the second chamber 838. In other embodiments,venting panels 858 may be positioned in any suitable location in theinflatable curtain airbag 820, as further discussed below. Placement ofthe second chamber 838 and/or the venting panel 858 can be made toimpart desirable cushioning and venting characteristics to theinflatable curtain airbag 820.

FIG. 11 depicts yet another embodiment of an inflatable curtain airbag920, such as the inflatable curtain airbags 720, 820 discussed above.Embodiments of inflatable curtain airbag 920 are compatible withembodiments of the assembly 100 discussed above. In the illustratedembodiment, the venting panel 958 defines a boundary of one inflatablecushion segment 942 at or adjacent to the edge 954 of the inflatablecurtain airbag 920. As illustrated, the venting panel 958 is in fluidcommunication with an exterior of the inflatable curtain airbag 920. Inembodiments, the one inflatable cushion segment 942 may be configured todeflate more quickly than the remaining inflatable cushion segments 942of the first chamber 936. This embodiment may permit the inflation gasto egress from the interior of the inflatable curtain airbag 920 to theexterior of the inflatable curtain airbag 920. The inflatable curtainairbag 920 does not comprise a second chamber, like the second chamber838. As discussed above, a variety of different locations in theinflatable curtain airbag 920 are suitable for disposition of the ventpanel 958.

FIG. 12 shows another embodiment of an inflatable curtain airbag 1020that can resemble the inflatable curtain airbags 720, 820, 920 describedabove in certain respects, and that can be compatible with the assembly100. Whereas, the venting panels 758, 858, 958 in inflatable curtainairbags 720, 820, 920 comprise a plurality of slits 760, the ventingpanel 1058 in inflatable curtain airbag 1020 comprises an opening 1066.In other embodiments, venting panel 1058 may comprise more than oneopening 1066. The opening 1066 may be retained in a closed configurationby at least one fold of a portion of the venting panel 1058. The foldmay be secured in place by a fastening mechanism 1068. The fasteningmechanism 1068 may comprise one or more of stitching, adhesives, clips,welding, and/or other suitable fasteners.

In embodiments, the opening 1066 can be configured to transition from aclosed configuration to an open configuration when a volume of inflationgas in the first chamber 1036 reaches a predetermined value. In otherembodiments, the opening 1066 may be configured to transition from aclosed configuration to an open configuration when an internal pressureof the inflation gas in the first chamber 1036 reaches a predeterminedvalue. For example, the opening 1066 can be configured to open when thepressure differential across the opening 1066 approaches, reaches, orsurpasses a predetermined value. In one embodiment, the predeterminedvalue may be reached when a vehicle occupant strikes a deployedinflatable curtain airbag 1020 in a collision event.

In other embodiments, the venting panel 1058 may delay the inflation gasfrom moving out of the first chamber 1036 into the second chamber 1038when the opening 1066 is in a closed configuration, and the ventingpanel 1058 may permit the inflation gas to move more easily out of thefirst chamber 1036 into the second chamber 1038 when the opening 1066transitions to an open configuration.

FIGS. 13A and 13B are enlarged cross-sectional views of the inflatablecurtain airbag 1020 of FIG. 12 taken along line 13A-13A. FIG. 13Adepicts an embodiment of a venting panel 1058 in a closed configuration,and FIG. 13B depicts the embodiment of the venting panel 1058 of FIG.13A in an open configuration. In the embodiment illustrated in FIG. 13A,the fastening mechanism 1068 may comprise a tack stitch. In FIG. 13A theventing panel 1058 is depicted as being configured into a fold. Asillustrated, the fold can be secured by a tack stitch, wherein theopening 1066 (see also FIG. 13B) is substantially sealed. As shown inFIG. 13B, the tack stitch may be configured to break when the volume ofinflation gas in the first chamber 1036 reaches the predetermined value.In another embodiment, the tack stitch may be configured to break whenthe pressure of the inflation gas in the first chamber 1036 reaches thepredetermined level. In embodiments, the tack stitch may be configuredto permit the portion of the venting panel 1058 secured by the tackstitch to unfold and transition the venting panel 1058 from a closedconfiguration to an open configuration.

FIGS. 14A and 14B are enlarged cross-sectional views of the inflatablecurtain airbag 1020 of FIG. 12 taken along line 13A-13A depictinganother embodiment of a venting panel 1058. FIG. 14A depicts the ventingpanel 1058 in a closed configuration and FIG. 14B depicts the embodimentof the venting panel 1058 of FIG. 8A in an open configuration. Asdepicted in FIGS. 14A and 14B, the fastening mechanism may comprise oneor more straps 1070. In some embodiments, the straps 1070 may comprise atear seam wherein the tear seam is configured to break when the volumeof inflation gas in the first chamber 1036 reaches a predeterminedvalue. In another embodiment, the straps 1070 may be configured to breakwhen the pressure of the inflation gas in the inflatable curtain airbag1020 reaches a predetermined level. In embodiments, the straps 1070 maybe configured to permit the portion of the venting panel 1058 secured bythe straps 1070 to unfold and transition the venting panel 1058 from aclosed configuration to an open configuration. The venting panel 1058may be secured in a closed configuration by one or more straps 1070comprising tear seams. For example, there may be a first strap 1070coupled to a first side of the venting panel 1058 and a second strap1070 coupled to the second side of the venting panel 1058. The first andsecond straps 1070 may be configured to break when the predeterminedvalue is reached and thus aid in transitioning the venting panel 1058from a closed configuration to an open configuration. In someembodiments the strap 1070 may be coupled to the venting panel 1058 byone or more of stitching, adhesives, clips, and/or other suitablefasteners. In one example, the tear seam of the strap 1070 may beconfigured to break when a vehicle occupant strikes a deployedinflatable curtain airbag 1020 in a collision and/or rollover event.When the tear seam breaks the opening 1066 may be configured totransition from a closed configuration to an open configuration.

In embodiments, a first portion of the venting panel 1058 may be foldedover a second portion of the venting panel 1058 to substantially sealthe one or more openings 1066. In other embodiments, a first portion ofthe venting panel 1058 may be formed into a single fold, a secondportion of the venting panel 1058 may also be formed into both a firstfold and a second fold, and the single fold may be disposed between thefirst and second folds to substantially seal the one or more openings1066. The folding configurations described above may further be securedby a tack stitch or other suitable fastener.

Referring again to FIG. 12, in some instances, the one or more ventingpanels 1058 can be configured to delay the inflation gas present in theone or more inflatable cushion segments 1042 from moving from theinflatable cushion segments 1042 to the second chamber 1038 when the oneor more openings 1066 are in a closed configuration. In other instances,the venting panels 1058 can be configured to permit the inflation gaspresent in the inflatable cushion segments 1042 to move more easily fromthe inflatable cushion segments 1042 into the second chamber 1038 whenthe openings 1066 are in an open configuration.

FIG. 15 depicts another embodiment of an inflatable curtain airbag 1120such as the inflatable curtain airbag 1020 discussed above. Embodimentsof the inflatable curtain airbag 1120 are compatible with embodiments ofthe assembly 100 discussed above. A first inflatable cushion segment1142 of the inflatable curtain airbag 1120 is positioned proximally tothe throat portion 1126 and below the throat liner 1127. A secondchamber 1138 is positioned distally to the first inflatable cushionsegment 1142. The venting panel 1158 defines a boundary between thefirst inflatable cushion segment 1142 and the second chamber 1138. Inother embodiments, venting panels 1158 may be positioned in any suitablelocation in the inflatable curtain airbag 1120. Placement of the secondchamber 1138 and/or the venting panel 1158 can be made to impartdesirable cushioning and venting characteristics to various portions ofthe inflatable curtain airbag 1120.

FIG. 16 depicts another embodiment of an inflatable curtain airbag 1220such as the inflatable curtain airbags 1020, 1120 discussed above.Embodiments of the inflatable curtain airbag 1220 are compatible withembodiments of the assembly 100 discussed above. In the illustratedembodiment, the venting panel 1258 defines a boundary of one inflatablecushion segment 1242 at or adjacent to the edge 1254 of the inflatablecurtain airbag 1220. As illustrated, the venting panel 1258 is in fluidcommunication with an exterior of the inflatable curtain airbag 1220. Inembodiments, the one inflatable cushion segment 1242 may be configuredto deflate more quickly than the remaining inflatable cushion segments1242 of the first chamber 1236. This embodiment may permit the inflationgas to egress from the interior of the inflatable curtain airbag 1220 tothe exterior of the inflatable curtain airbag 1220. The inflatablecurtain airbag 1220 does not comprise a second chamber, like the secondchamber 1138. As discussed above, a variety of different locations inthe inflatable curtain airbag 1220 are suitable for disposition of thevent panel 1258.

FIGS. 17A and 17B show another embodiment of an inflatable curtainairbag 1320 that can resemble the inflatable curtain airbags 720, 1020described above in certain respects, and that can be compatible with theassembly 100. The inflatable curtain airbag 1320 of the illustratedembodiment includes a venting panel 1358 that defines a boundary betweenthe first chamber 1336 and the second chamber 1338. The venting panel1358 comprises a loop 1372 at a proximal end of the venting panel 1358.In embodiments, the loop 1372 can be configured to releasably couple theventing panel 1358 to an interior surface of the inflatable curtainairbag 1320. Additionally, the loop 1372 may be configured to transitionfrom a coupled configuration (see FIG. 17A) to an uncoupledconfiguration (see FIG. 17B) when a volume of inflation gas in the firstchamber 1336 reaches a predetermined value.

In some embodiments, the venting panel 1358 may delay the inflation gasfrom moving out of the first chamber 1336 into the second chamber 1338when the loop 1372 is in a coupled configuration. When the loop 1372 isin an uncoupled configuration, the venting panel 1358 may be configuredto permit the inflation gas to move more easily out of the first chamber1336 and into the second chamber 1338.

The distal end of the venting panel 1358 at or adjacent to the loop 1372may retract away from the interior surface of the inflatable curtainairbag 1320 to form a vent or opening in the interior of the inflatablecurtain airbag 1320 for the passage of inflation gas from the firstchamber 1336 to the second chamber 1338. The loop 1372 may be releasablycoupled to the interior surface of the inflatable curtain airbag 1320 bya fastener 1368. In embodiments the fastener 1368 can be selected fromat least one of adhesives, hook-and-loop fasteners, tack stitching,tapes, and/or straps comprising tear seams. As described above, theventing panel 1358 may be configured to optimize the relative internalpressures of the first and second chambers 1336, 1338 in a deployedinflatable curtain airbag 1320.

In embodiments, the inflatable cushion airbags 720, 820, 920, 1020,1120, 1220, 1320 may be modified to be compatible with embodiments ofthe assembly 400 discussed above.

Any methods disclosed herein include one or more steps or actions forperforming the described method. The method steps and/or actions may beinterchanged with one another. In other words, unless a specific orderof steps or actions is required for proper operation of the embodiment,the order and/or use of specific steps and/or actions may be modified.

Reference throughout this specification to “an embodiment” or “theembodiment” means that a particular feature, structure or characteristicdescribed in connection with that embodiment is included in at least oneembodiment. Thus, the quoted phrases, or variations thereof, as recitedthroughout this specification are not necessarily all referring to thesame embodiment.

Similarly, it should be appreciated that in the above description ofembodiments, various features are sometimes grouped together in a singleembodiment, figure, or description thereof for the purpose ofstreamlining the disclosure. This method of disclosure, however, is notto be interpreted as reflecting an intention that any claim require morefeatures than those expressly recited in that claim. Rather, as thefollowing claims reflect, inventive aspects lie in a combination offewer than all features of any single foregoing disclosed embodiment.Thus, the claims following this Detailed Description are herebyexpressly incorporated into this Detailed Description, with each claimstanding on its own as a separate embodiment. This disclosure includesall permutations of the independent claims with their dependent claims.

Recitation in the claims of the term “first” with respect to a featureor element does not necessarily imply the existence of a second oradditional such feature or element. Elements recited inmeans-plus-function format are intended to be construed in accordancewith 35 U.S.C. §112(f). It will be apparent to those having skill in theart that changes may be made to the details of the above-describedembodiments without departing from the underlying principles of theinvention. Embodiments of the invention in which an exclusive propertyor privilege is claimed are defined as follows.

1. An inflatable curtain airbag assembly comprising: an inflatablecurtain airbag having a longitudinal orientation, the inflatable curtainairbag comprising; a throat portion in fluid communication with aninflator; a throat liner in fluid communication with and disposed withinat least a portion of the throat portion, and wherein the throat linerextends in the longitudinal orientation of the inflatable curtain airbagaway from the throat portion; a first chamber in fluid communicationwith the throat liner comprising a plurality of inflatable cushionsegments; and one or more venting panels defining a boundary of one ormore of the inflatable cushion segments comprising at least one opening,wherein the opening is retained in a closed configuration by at leastone fold of a portion of the venting panel, wherein the fold is securedby a fastening mechanism, and wherein the opening is configured totransition from a closed configuration to an open configuration when avolume of inflation gas in the first chamber reaches a predeterminedvalue.
 2. The inflatable curtain airbag assembly of claim 1, wherein theventing panel delays the inflation gas from moving out of the firstchamber when the opening is in a closed configuration, and wherein theventing panel permits the inflation gas to move more easily out of thefirst chamber when the opening transitions to an open configuration. 3.The inflatable curtain airbag assembly of claim 1, wherein the ventingpanel defines a boundary between a first inflatable cushion segment andan exterior of the inflatable curtain airbag, and wherein the firstinflatable cushion segment is configured to deflate more quickly thanthe remaining inflatable cushion segments of the first chamber.
 4. Theinflatable curtain airbag assembly of claim 1, wherein the inflatablecurtain airbag further comprises a second chamber, and wherein theventing panel defines the boundary between the second chamber and afirst inflatable cushion segment, and wherein the first inflatablecushion segment is configured to deflate more quickly than the remaininginflatable cushion segments of the first chamber.
 5. The inflatablecurtain airbag assembly of claim 1, wherein the predetermined value isset to be reached when an occupant strikes at least one of theinflatable cushion segments in a collision.
 6. The inflatable curtainairbag assembly of claim 1, wherein the fastening mechanism comprises atack stitch, and wherein the tack stitch secures the portion of theventing panel in a folded configuration.
 7. The inflatable curtainairbag assembly of claim 1, wherein the fastening mechanism comprises atleast one strap comprising a tear seam.
 8. The inflatable curtain airbagassembly of claim 7, wherein the strap is configured to break at thetear seam when an occupant strikes the inflatable curtain airbag in acollision, and wherein the opening is configured to transition to anopen configuration when the strap breaks.
 9. The inflatable curtainairbag assembly of claim 1, wherein the inflatable curtain airbagcomprises two straps, and wherein a first strap is coupled to a firstside of the fold of the venting panel and a second strap is coupled tosecond side of the fold of the venting panel.
 10. The inflatable curtainairbag assembly of claim 1, wherein a first portion of the venting panelis folded over a second portion of the venting panel and wherein thefold substantially seals the opening.
 11. The inflatable curtain airbagassembly of claim 1, wherein a first portion of the venting panel isformed into a single fold, wherein a second portion of the venting panelis formed into both a first fold and a second fold, wherein the singlefold is disposed between the first and second folds, and wherein thedisposition of the folds is configured to substantially seal theopening.
 12. The inflatable curtain airbag assembly of claim 11, whereinthe folds are coupled by tack stitching.
 13. An inflatable curtainairbag assembly comprising: an inflatable curtain airbag having alongitudinal orientation, the inflatable curtain airbag comprising; athroat portion in fluid communication with an inflator; a throat linerin fluid communication with and disposed within at least a portion ofthe throat portion, and wherein the throat liner extends in thelongitudinal orientation of the inflatable curtain airbag away from thethroat portion; a first chamber in fluid communication with the throatliner comprising a plurality of inflatable cushion segments; and asecond chamber comprising at least one inflatable cushion segment and atortuous vent, wherein the inflatable cushion segment is in fluidcommunication with both of the throat liner and the tortuous vent, andwherein the tortuous vent is configured to delay inflation gas frommoving out of the second chamber.
 14. The inflatable curtain airbagassembly of claim 13, wherein the first chamber extends in alongitudinal orientation along about two thirds of a length of theinflatable curtain airbag, and wherein the second chamber extends in alongitudinal orientation along about one third of the length of theinflatable curtain airbag.
 15. The inflatable curtain airbag assembly ofclaim 13, wherein the tortuous vent is configured to permit passage ofthe inflation gas when a volume of inflation gas in the second chamberreaches a predetermined value.
 16. The inflatable curtain airbagassembly of claim 13, wherein the tortuous vent is substantiallyU-shaped.
 17. The inflatable curtain airbag assembly of claim 13,wherein the predetermined value is set to be reached when an occupantstrikes the second chamber in a collision.
 18. The inflatable curtainairbag assembly of claim 13, wherein the second chamber is positioned ator adjacent to a C-pillar of a vehicle.
 19. The inflatable curtainairbag assembly of claim 13, wherein the second chamber is positionedrearward to a B-pillar of a vehicle.
 20. The inflatable curtain airbagassembly of claim 13, further comprising a third chamber in fluidcommunication with a distal end of the tortuous vent.